On January 30 1969, The Beatles — the band that had reshaped popular music and culture in a creative arc of only eight years (and with whom I had worked for that entire dizzying period) — played an impromptu show in London, immortalised as “the rooftop concert”. The six-song set was staged atop 3 Savile Row, the building we had bought as the headquarters for their adventurous multimedia company, Apple Corps. Although none of us realised it at the time, it was to be their final live performance as a band. And as far as rock shows go, it was a great one. On that freezing rooftop in London, I saw and heard everything that was great about The Beatles. The humour, the look (John and Ringo wore their wives’ coats for the performance) and, of course, the music. But I also saw the frayed ends and the bitterness that was already spilling out in my office at Apple, where I had been appointed as executive director the year before, having spent most of the 1960s at Brian Epstein’s management company.